Gauge



&

March 23, 1937.

Filed Dec. 15, 1933 J. M cLAlN 2,074,753

GAUGE 2 Sheets-Sheet 1 March 23, 1937. J. McCLAlN 2,074,753

I GAUGE Filed Dec. 15, 1933 2 Sheets-Sheet 2 Patented M...123,1937 I UNITED STAT omen. John mourn, cum, m. V Application December 15, 19:3. Serial No. 702,541. 8 Claims. (CL-177411.)

The invention relates generally to gauges, and

w more particularly to gauges adapted to measure or test the diameter of elongated cylindrical -members such as the tubes of a boiler or heater.

In the practice of certain oil-distilling or cracking processes, the high pressure and/or intense heat employed cause distortion and bulging of weak sections of the boiler. tubes, and as the operation of the heater continues, the bulged areas gradually enlarge until failure results.

Loss due to thiscause is in practice reduced by frequent tests of the tubes between periods of operation whereby to detect weakness in the tubes as indicated by such distortion and insure re- 15 placement of the weakened tubes before failure thereof.

The primary object, therefore, of the present invention is-to provide a new and improved gauge adapted to determine whether or not there are material bulges or variations in diameter in an. elongated pipe or tube such as the tube oiaboiler.

through a pipe or tube "within which is illusall till

trated an internal gauge embodying the features oi the invention, a portion of the gauge mechanism being shown diagrammatically.

Fig. 2 is a view taken partially in longitudinal central section through the gauge head.

Fig. 3 is an end elevational view of the gauge head shown in Fig. 2, a portion of the view being taken in section to illustrate the interior construction oi the head. I

Fig. i is an elevational view of a reference dish mounted on the. actuating rod oi the device, the view being taken along the line ti i oi Fig. 1.

Fig. 5 is a sectional View showing an alternative iorm oi guide construction.

his. 6 is a longitudinal central sectional view through an alternative form of gauge head adapted for use in gauging or measuring the Fig. 8 is a sectional view of an form of feeler construction.

. Fig. 9 is a sectional view showing an alternative form of guide construction.

While I have shown in the drawings and will herein describe in detail but two embodiments of the major features of my invention, it is to alternative I be understood that I do not thereby intend to limit the. invention to the specific forms dis-' closed, but aim to cover all modifications and alternative constructions falling within the spirit and scope of the invention as' expressed in the appended claims.

Each of the two forms of the invention illustrated herein embodies a gauge head adapted for movement longitudinally of a tube in concentric relation thereto so that a plurality of Es PATENT. OFFICE] circumferentially spaced feelers carried by the head and riding in contact with the adjacent surface of the tube serve to discloseradial distortion of the tube. Such distortion and its 10- cation circumferentially of the tube are made known to the remotely stationed operator by a plurality of indicating devices controlled independently by the several feelers.

The exemplary embodiment of the invention illustrated in Figs. 1 to .4 of the drawings constitutes an internal gauge and comprises a gauge head it adapted for movement longitudinally through a boiler tube H or the like by means of a tubular rod i2 upon which the head is mounted. As the head is moved through the tube i i a pinrality of circumierentially spaced radially mov- I I able. ieelers iii mounted on the head it are constantly urged outwardly oi the head so as to maintain contact with the inner surface of the or the feelers iii, a plurality of resilient radially projecting guides it are positioned at opposite ends of. the head in circumferentially spaced relation so as to ride along the inner surface oi the tube ill. Similarly, a plurality oi. restslor guide disks it are mounted in longitudinally spaced relation on the rod it so as to prevent handing or sagging of the rod and consequent misalinement oi the gauge head it.

When, in the movement of the head iii through a tube it, one of the feelers it shifts outwardly a predetermined distance into a, wealiened or bulged area it (Fig. 3) in the tube, this particular feeler acts, preferably through electrical means, to control its remotely located indicator such as a light it which iorrns a part at" an has I8 in Fig. 1.

Since the gauge head I0 may be rotated from time to time during its movement through the tube, a reference plate I9 is secured to the rod I2 adjacent to its end so as to facilitate determination of the angular location of the area I5. The plate I9 carries identification numerals 20, as shown in Fig. 4, which correspond with the connections between the feelers I3 and the indicator lights II, which are correspondingly numbered.

The gauge head III, as shown in Figs. 1 to 3.

comprises a cylindrical housing having cupshaped end caps 2|, the side walls 22 of which are detachably secured by screws 23 to opposite ends of a central ring 24. With this construction, the feelers are preferably carried by the central ring 24, while the end caps 2| carry the guides I4 and provide for screw threaded axial connections 25 with the portions of the rod I2 which extend in opposite directions from the gauge head.

The guides I4, in the form shown in Figs. 2 and 3, comprise resilient metal strips 26 extending radially along the inner end surface of the end caps 2| and outwardly through apertures 21 in the side walls 22 thereof. The outer projecting ends of the strips 26 are bent as at 28 to curvedor arcuate form to provide for resilient sliding contact with the inner surface of the tube II. To permit radial adjustment of the guides I4, radial slots 29 are formed ln-the strips 26, and bolts 30 extend through the end walls of the end caps 2| and through the slots 29 to receive clamp nuts 3|. Slotted heads 32 on the bolts 33 permit adjustment of the guides from the exterior of the guide head III.

Within the central ring 24, which is formed from metal, a ring 330i insulating material is 4 fixed to carry the electrical control for the indicator l8. Each feeler I3 preferably comprises a plunger 34 (Fig. 3) formed from metal and carrying a. bearing ball 35 at its outer end to reduce the friction between the plunger and the tube .through which it is moved. Alined bores 36 in the rings 24 and 33 support the plunger 34 for radial movement, and the inner end of the plunger, which extends inwardly beyond the inner surface of the insulating ring 33, has a rednced portion 31 which slides in a. coaxial bore 38 of reduced diameter in the ring 33. Surrounding the reduced portion of the plunger 34 within the bore 36 is an expansive coil spring 39 which acts to urge the plunger outwardly into contact with the inner surface of the tube to be tested.

At its projecting inner end each feeler I3 is associated with a contact clip 49 mounted on the insulating ring 33 in such a manner as tolimit the movement of the feeler, preferably in both directions. Each clip is formed from metal to provide a side member 4|, which is secured in radially extending position on the side 01' the ring 33 adjacent to one of the feelers I3 by means of a screw 42, with a pair oi abutment or contact plates 43 projecting from the side member 4| into the path of its radially movable feeler. The abutment plates 43 are spaced from each other along the path of movement of the feeler and suitable apertures 44 are formed in the plates so that the feeler may extend and move through the plates without lateral contact with the plates as determined by an adjustable contact member 45 screw threaded on the reduced portion 31 of .the feeler intermediate the contact plates 43.

While the outer end of a feeler I3 .15 1. abut 2,074,753 dicator mechanism shown diagrammatically at ment with the interior of a truly cylindrical tube II of the size for which the gauge is intended, the member 45 on the inner end of that feeler rides substantially midway between the contact plates 43, and when a bulged area such as the portion I6 (Fig. 3) is encountered, the member 45 is shifted outwardly into contact with the outer plate 43. Conversely, the presence of scale or any similar obstruction in the tube will shift the stop 45 into contact with the inner plate 43.

Individual electric circuits are provided (Figs. 1 and 3) from the several feelers I3, a plurality of wires (6 being employed which extend from the several lights II of the indicator through the rod I2 and into the gauge head II) where they are connected to the several clips by means of their mounting screws 42. A common lead wire 41 connected to all of the lights I1 and in circuit with a power source 48, also extends through the rod I2 and is connected to the metal ring 24 by a screw 49 (Fig. 3). Thus the plates 43 and the member constitute a switchand movement of a particular feeler until its member 45 engages either of the contact plates 43 establishes a. circuit through the corresponding light H of the indicator.

Accurate, finelygraduated and easily performed adjustment of the feelers l3, as well as the guides I4, is highly desirable, and in Figs. 5, 8 and 9 various alternative constructions are illustrated which satisfy these requirements. Fig. 5 discloses a'guide construction wherein an arm 50 is screw threaded radially into the end cap 2| of the head, a. lock nut 5| being provided for fixing the arm in adjusted position. At its projecting outer end the arm 50 carries a bearing ball 52 which is held within the constricted outer end of a bore 53 and is urged outwardly by an expansive spring within the bore. j

A generally similar construction is illustrated in Fig. 8 as applied to one of the feelers I3, the plunger 34 having a screw threaded axial bore 54 at its outer end into which a stem 55 is threaded. A look nut 56 on the stem provides for fixing the stem'in the desired adjusted position. At its outer end the stem-carries a head 51 in which an outwardly facing bearing ball 58 is mounted. Fig. 9 discloses an alternative form of guide I4 wherein abolt 59 carrying a pair of nuts 60 is screw threaded into a radial bore in the head III. The inner one of the nuts 50 serves as a conventional lock nut, while the outer nut 60 clamps one end of a resilient metal strip 6| against the bolt head 62. The strip is reversely bent to over- -lie the bolt head 62 so as to provide for resilient sliding contact with the interior of a tube.

In Figs. 6 and '7 the invention is illustrated as embodied in an external gauge adapted to measure or test a tube by contact with various portions of the external surface thereof. In the form shown, the external gauge head comprises an'elongated sleeve 65 adapted to surround and slide along a tube II in spaced concentric relation thereto as determined by a plurality of resilient guides 56 located at the ends of the sleeve 65 and in spaced circumferential relation to each other. trated, comprise a resilient metal strip fixed at one end to the end of the sleeve 65 by a screw 61, and extending into the sleeve. The inner end of the guide 66 is bent to arcuate form as shown at 68 to facilitate sliding contact with the pipe, and radial adjustment of each guide may be effected by means of a screw 69 threaded radially through the sleeve and engaging the guide be- Each guide may, as in the form illustween the. curved portion 68 and the end of the sleeve. a K Radially movable feelers 10 are provided of substantially the same construction as in the em- I 15 bodiment of Figs. 1 to 4, except that he feelers It are reversed so as to be pressed I adially in wardly from an insulating ring It which surrounds and is fixed upon the sleeve 65 intermediate its ends. Similar electrical connections and 10 clips at are employed hereby the external gaugev may he associated .it suitable indicating mechanism caches the illustrated in Fig; 1. A twopart housing-"I2, l2 is'mounted on the sleeve 65 and serves to protect and enclose the clips and 15 other; mechanism of the gauge head in a degree coparahle to the enclosure of the mechanism in the head it of the internal gauge. These parts preierably separable to give access to the contact mechanism.

item the foregoing it will he evident that the invention provides a simple and'eflectlve gaugepermissihle variation may he readily adjusted hy,

manipulation oi parts located eirteriorly oi the gauge head.

y l claim as my invention: 7

3i) .d gauge comprising a head, an insulating ring carried by said head, a plurality oi plungers slidahle substantially radially through said insulating ring, yieldahle means urging said plungcrs in one direction, a plurality oi clips s mounted on said ring, each of said clips having two radially spaced contact elements located adiacent to the path oi movement oi one oi said pltmgers, contact means on each of said plungers adapted to engage said contact elements oi the 5 adiacent clip in both directions oi movement,

and a plurality oi electric indicating devices each having a control circuit including one oi the plungers and its associated clip in series.

2. ll gauge comprising, in combination, a head adapted to he moved along a tube in concentric relation thereto, a plurality of ieelers mounted on said head at spaced points circumierentially thereof for movement substantially radially oi said head throughout a limited range, spring means urging said ieelers toward one limit of their range of movement, remotely located indicating means having a plurality oi electrically controlled indicating devices, one device being provided for each of said feelers, individual conto trol circuits for said devices each including separate switch means having two spaced clcsedpositions and an intermediate open position, and connections between each ieeler and its switch means operable to move said switch to one oi its as closed positions when said feeler reaches either limitoi its range. I

i. ii gauge for detecting radial irregularities oi a tuhe comprising a head adapted to be moved along the tube, a plurality of feelers mounted on said head ior independent movement radially inwardly or outwardly-of the head, means urging said feelers in one direction radially, a plurality oi indicators located remotely with respect to said head providing one indicator for each oi said 7s ieelers, normally open individual circuits for each indicator, and means including saidv feelers closmg each individual circuit upon a predetermined movement of the corresponding one of said feelers radially inwardly or outwardly of said head.

4. A device of the character described com prising a head adapted to be moved through a hollow member, resilient guide means mounted for radial adjustment on said head and adapted to center the head in such'a member as it is moved therethrough, a plurality of feelers mounted on said head at circumferentially spaced points for movement radially thereof, means urging said feelers outwardly into contact with the inner surface of such a member, remotely located indicating means having an indicating device for each oi said feelers, a plurality of switches each comprising stationary contact means mounted on the head and a movable contact actuated by one oi said ieelers, an individual electrical circuit be:

tween a ieeler and its indicating device includingone oi said switches through which each ieeler energizes its particular indicating device upon predetermined movement of the particular ieeler with relation to the head, and adiustahle'means carried by said ieelers for coordinating the radial position'oi the ieelers at which energiaation oi the indicating devices talres place with a radial adjustment of the guides.

, h. it. gauge ior indicating irregularities in tubes comprising, in comhination, a central ring andend caps secured to said ring to form a hollow gauge head adapted to be'inserted into a tube, guide means carried hy said end caps ior engaging the inner surface oi thetuhe to center the head rtherein, an insulating ring mounted in saidcentral ring, a plurality oi ieelers projecting outwardly from said central ring ior contact with the tube at circumierentiallyspaced points about the ring and mounted in said central ring for radial movement, means urging said ieelers-out-- wardly, individual normally openswitch means for each of said ieelers comprising a contact movahle with the ieeler and cooperating contact means mounted on said insulating ring and disposed to he engaged by the movable contact upon predetermined movement oi the ieeler, a plurality oi remotely located electrically operated indicating devices, and an individual circuit hetween eachswitch means andthe indicating device of its'particular ieeler.

d. A gauge comprising, in combination, a sleeve, guide means adjacent opposite ends oi the sleeve adapted to engage the outer surface of a tube to maintain the sleeve in coaxial relation there" to, a plurality oi feelers mounted on said sleeve for substantially radial movement and projecting from the outer side thereoi through the sleeve for contact with such a tube at a plurality oi circumierentially spaced points, means ior urging the feelers into contact with the tube, an inall sulating ring encircling and mounted on said sleeve, a plurality of contact means mounted on said insulating ring, one for each feeler, a movable device including in-series the contacts oi its ieeler.

Y '1. A gauge for indicating irregularities in a tube comprising a head having guide means for centering the head with respect 'tothe tube, a plurality of feelers spaced circumferentialiy about the head and mounted therein for sliding movement radially with respect to the center of the head, means for normally urging said feelers in one direction radially of the head, an elongated,

8. A gauge comprising a head adapted to be moved along a tube, guide means on the head for centering the same with respect to the tube, a plurality of feelers spaced circumferentialiy about the head and mounted thereon for movement radially with respect to the center 01' the head,

means for normally urging the feelers in one direction radially, a switch device for each feeler comprising fixed radially spaced contacts and a contact movable with the feeler and disposed between the fixed contacts, said movable contact being normally out of engagement with both fixed contacts and operable upon predetermined movement of the feeler in either direction radially to engage one of the fixed contacts, and means operable to indicate'irregularities detected by said feelers and'including connections from said switch devices to said last mentioned means.

JOHN McCLAIN. 

